I found that the qtest used in a Delaunay triangulation algorithm was difficult to emulate with an ANN.

qtest determines if a point is in- or out-side the circumcircle of a triangle specificied by 3 other points. It seems that the critical missing feature for the ANN is the center of the circumcircle. This suggests that the ANN is no able to model this type of calculation. However, all of features in the calculation where readily modeled.

I created a Jupyter notebook for these tests, available here or viewed online at GitHub.